Bolster gardening confidence by growing radishes

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Last Updated:

February 19, 2003

CORVALLIS - Is your thumb black instead of green? Does any plant you touch seem to wither and die? Get your gardening confidence back by growing radishes this spring. Radishes are a cool season root crop, according to Ross Penhallegon, horticulture agent with the Oregon State University Extension Service. Varieties include the traditional round red radishes, the large, sleek Oriental radishes and newer novelty types like Easter Egg, which grows in shades of red, white, purple and rose. "Radishes are easy to grow and don't take up much space," said Penhallegon. "They can be planted in the spring and again later in the summer for a fall crop. For a continuous supply, plant some seed every 10 to 15 days throughout the season. In the heat of summer they may become woody and hot, so it is best to plant them during cooler times of the year. A four-foot row will usually produce enough for a family of four."

OSU Extension recommends the following varieties of radishes as performing well in Oregon conditions:

Before planting, spade the soil and work in some well-balanced fertilizer and plenty of organic material. Penhallegon recommends adding the equivalent of one pound of 16-20-0 fertilizer or two pounds of 5-10-5 fertilizer into each 100 square feet. Ten pounds of good compost or manure will also work, he said.

Plant the seeds 1/2 inch deep. Radishes can be planted among other plants such as beets or carrots for maximum production in a small space.

Water radish seeds thoroughly after planting, making sure the water wets the soil down to 6 inches deep. Keep seeds moist until they sprout. Thin the plants to an inch apart soon after they come up.

"Don't let the soil dry out - the secret to good radishes is to keep them growing fast," he said.

Harvest radishes 3 to 4 weeks after planting. If they are left in the ground too long, they may split, crack, or become pithy. They are best eaten as soon as possible after harvesting. Oriental radishes are much bigger than most of the radishes grown in the United States. Oriental varieties include Daikon and other types, many of which grow to more than a pound. The Sakuajima Mammoth radish has been known to top 100 pounds.

These jumbo radishes generally mature in about 60 to 70 days and can be pickled, breaded and fried in oil or sliced and slightly cooked and added to many stir fry dishes. Oriental radishes are best planted in late summer, as they bolt with June's long days. A few pests occasionally attack radishes when the weather turns warm, including flea beetles and cabbage maggots. Covering seedbed with floating row cover-type material or planting early or late in the season can prevent infestations.